Improvements in an input/output control (I/O control) system will most likely lead to a reduction in queue size and queue time. An I/O control system is a method of managing the flow of work orders in a production system by matching the input rate to the output rate. The input rate is the number of work orders that are released to the shop floor in a given period. The output rate is the number of work orders that are completed and shipped to the customers in a given period. An I/O control system aims to keep the input rate equal to the output rate, or slightly lower, to avoid overloading the system and creating excess inventory. By improving the I/O control system, the production system can achieve a smoother and more balanced flow of work orders, which reduces the queue size and queue time at each work center. Queue size is the number of work orders that are waiting to be processed at a work center. Queue time is the amount of time that a work order spends in the queue before being processed. A reduction in queue size and queue time can improve the production efficiency, quality, and flexibility, as well as the customer service and satisfaction. The other options are not correct, as they are not the most likely outcomes of improvements in an I/O control system, but rather possible effects of other factors or methods:

Flattened bills of material (BOMs) are the result of simplifying the product structure and reducing the number of components or levels in a BOM. Flattened BOMs can reduce the complexity and lead time of the production process, but they are not directly related to the I/O control system.

A change in operation sequencing is the result of altering the order or priority of the work orders or operations in a production system. A change in operation sequencing can affect the production flow and capacity, but it is not necessarily caused by the I/O control system.

Fewer engineering change notifications are the result of minimizing the changes in the product design or specification during the production process. Fewer engineering change notifications can reduce the disruption and cost of the production process, but they are not directly related to the I/O control system. References:

[CPIM Part 2 - Section A - Topic 2 - Capacity Planning]

Input/Output Control | SpringerLink

Input/Output Control - an overview | ScienceDirect Topics

Input/Output Control - InventoryOps.com